LOS ANGELES (AP) — Tens of thousands of demonstrators opposed to Arizona’s tough law marched through the streets of downtown Los Angeles to demand an overhaul of immigration laws, some holding signs calling for a boycott of the Grand Canyon State.

Singer Gloria Estefan kicked off the march by climbing on a flatbed truck to say that illegal immigrants should not be considered criminals. She said the United States was a nation of immigrants.

“We’re honest people, we’re good people,” the Cuban-born singer said. “We’ve given a lot to this country. This country has given a lot to us.”

Cardinal Roger Mahony stood on the truck and joined the crowd in chanting, “Si, se puede,” or “Yes, we can,” in Spanish. Streets and sidewalks were packed with tens of thousands of people as horns blared.

The march ended nearly five hours later after a steady stream of politicians and labor leaders stepped on stage to denounce the Arizona law and insist that President Barack Obama tackle immigration reform.

“We say no to Arizona, no to racism, no to hate,” said Janice Hahn, a Los Angeles city councilmember and Democratic candidate for California lieutenant governor.

Police officials estimated about 50,000 demonstrators took to the streets at the rally’s peak in the early afternoon.

Police had prepared for an anticipated 100,000 people, and a ground force of officers on foot, bicycles, and motorcycles were making patrols.

Two people were arrested, one for vandalism and one for public drunkenness, Los Angeles Police Officer Cleon Joseph said.

Organizers handed out T-shirts that read, “Legalize Arizona” and “Boycott Arizona.” Marchers waved American flags, along with many from other countries, including Mexico, the Philippines, Nicaragua, and Guatemala.

David Cho, an illegal immigrant from Korea and a student at the University of California, Los Angeles, drew loud cheers when he said he dreamed of joining the Air Force and becoming a U.S. senator.

“I feel like I’m living inside an invisible prison cell,” he said.

Many came to protest Arizona’s new law requiring local and state law enforcement officers to question people about their immigration status if there’s reason to suspect they’re in the country illegally.

“If they see someone with black hair and a Latino face, they’re going to stop you without any reason and ask for your papers,” said Eleazar Cruz, 37, a Los Angeles bartender from Mexico who paid a smuggler $300 to cross the border illegally in San Diego in 1985 and later became a legal resident. “It’s crazy.”

Cruz participated in a massive May 1 pro-immigration march in 2006 — upset at the time by a proposed federal crackdown on illegal immigration — but was too busy to attend the annual marches since then. The Arizona law brought him back. “We’re angry,” he said.

Oswaldo Osorio, an illegal immigrant from Mexico whopaid his smuggler $150 to cross the border in San Diego 18 years ago, turned out with his wife, also in the United States illegally, and their two U.S.-born daughters. All four waved American flags.

Osorio, 38, said his family wanted to make a statement for giving immigrants legal status and protesting Arizona’s law.

Benjamin Hernandez, 44, attended his first political rally since coming to the United States illegally 10 years ago. He lived in Arizona for two years after paying a smuggler $1,200 to walk across the desert, then moved to Ventura to join his father, where he works in construction.

Hernandez said his nephews in Arizona are upset by the law but won’t leave the state.

“I won’t go visit them,” he said. “They can come visit me. After working so hard, why would I want to lose everything?”

There were few dissenting voices. Demonstrators ignored a man who stood silently on a sidewalk as they walked past him with a sign that read, “Balance the Budget. Deport Illegal Aliens.”

In San Francisco, a crowd believed to be in the thousands marched through the Mission District to a rally at the city’s Civic Center.

Police were out in force, lining the route as the noisy crowd chanted and carried signs reading “Full Rights For All Immigrants” and “Arizona’s Racist Law, We Say No!”

Juan Carlos Esteban, 37, a member of the United Service Workers West union, said he felt the need to protest the Arizona legislation.

“That’s a step backward for the whole nation,” he said of the law. “It’s a human rights issue.”

Noe Madrigal, 32, came out with 15 friends. He said that only two of them were in the country legally.

“That new law in Arizona is very unfair,” Madrigal said. “That’s racism.” ♦

Associated Press writer Sudhin Thanawala contributed to this report from San Francisco.